Best Filler to use over Leadwork
 

We always used Duraglas years ago but wondered if there is currently anything better. Thanks for any suggestions.
Chuck

Re: Best Filler to use over Leadwork
 

The issue with filler over lead has mostly been with any acid residue. Polyester, which most plastic body fillers are, DOES NOT LIKE ACID. Best bet is to neutralize any acid, make sure any other flux is cleaned off, and primer with a epoxy or urethane (extra respiratory protection with urethane!!!) primer. Then filler over the primer.

Re: Best Filler to use over Leadwork
 

I always used a mixture of baking soda to clean after tinning.Also use baking soda on the lead ,before filing. Agree the best is epoxy primer over the lead then filler

Re: Best Filler to use over Leadwork
 

Chuck, Can you elaborate a bit please? Is this old, original factory lead, or recently applied? When leading, I've always used 'Fluxite' paste, it is non acidic, and doesn't have the inherent problems one gets when using spirits of salt type fluxes....

Re: Best Filler to use over Leadwork
 

If its old lead you should seriously consider removing it. I melted the lead out of my '40's tailpan joins and found rust below.

Re: Best Filler to use over Leadwork
 

I have always removed all of the old lead. When considering all the work involved to get my cars to the point of completion, well, I won't risk the potential for any issues later.
I have found that the amount of lead applied at the factory was typically excessive. Probably because it was a fast-moving assembly line.
A typical area on the '39 / '40 Fords was where the rear tail pan was welded to the quarter panels. Once I remove the lead, I weld a metal patch to bridge that area, metal work and later, as necessary, apply a small amount of filler/
Nope, NO lead for me.

Re: Best Filler to use over Leadwork
 

Seriously, this surprises me, as I had always heard that "the pros use lead".

I guess that's another "old wives tale" put out to pasture.

Re: Best Filler to use over Leadwork
 

I knew a guy that was perhaps arguably, one of the best body / paint guys in the country. Pebble Beach stuff time and again. He'd use nothing but lead.

Me? I was always fearful of the lead coming back to haunt after the car was painted. That may be from my lack of firsthand lead work (he had decades) or my experience with modern techniques.
I am proud in that he had me fully restore a '39 coupe for him after he retired and was no longer able to do the work. That was quite a compliment to me, coming from him.

Re: Best Filler to use over Leadwork
 

Lead vs Plastic filler...


Its not the medium, its the implementation.


Lead (well actually solder, as solder has not had lead in it for many years) requires careful preparation, skillful application, and effective cleanup. It can provide a better base for paint in many situations as it is closer to the hardness, flexibility, and thermal shrinkage rate of underlying steel than plastic fillers can be. This is most noticeable for filling irregular body seams (shrinkage/expansion) and also for dents in large slightly curved areas (avoiding "cupping" when sanding a transition from steel to filler). It does require special skill in molding and filing, and usually takes much more effort for a given amount of filler than plastic.


Plastic fillers also have their quirks that can also haunt you. Most plastic fillers are polyester, which is porous to water and attracts slight amounts of water. If not perfectly sealed from the base steel this moisture can result in rust forming on the surface of the steel under the filler and eventually separating the bond. Using a primer sealer under the filler solves this issue. Filling a sharp valley can create an area where thermal expansion/shrinkage can be noticeable under paint. Improper amount of hardener can result in all kinds of interesting and irritating effects from incomplete hardening or excessive hardening.


My father often commented to the effect that real pros metal finish to a point where filler usage is nominal. What Kube described as his reworking of Ford seams would have met his enthusiastic approval.


Lead filler, and plastic filler are both "tools in the toolbox" with specific best uses, with best results using what works and doing it absolutely correctly.

Re: Best Filler to use over Leadwork
 

Karl, I could not agree with you more. Perhaps it was pure "chicken" on my part, but I was never comfortable with lead, well, my knowledge (lack of) lead work.
I was also never comfortable with any more than a trace of filler anywhere. Yep, lots more work but the satisfaction at completion was worth it to me each and every time.

Re: Best Filler to use over Leadwork
 

So I guess the answer to the original question of this post is : None.

Re: Best Filler to use over Leadwork
 

I have only used lead on places like a thin door edge where it meets the jamb and strength is wanted. My metal work is close enough that high build primer is all that is usually needed. Like Mike said the overuse of it at factory seams is probably due to having less than perfect body joints due to production speed. Quickly done, easy to work and off to the painting steps. I was taught by someone who had a degree in autobody repair long before plastic filler was invented.

Re: Best Filler to use over Leadwork
 

Technically you are correct, because no filler should ever touch lead (or bare metal). It should only be used over a quality DTM (direct to metal) primer. These days I only use Tamco or Revolt. Even their high build is DTM, so if you block through to bare metal, you can just give it another coat & still have proper sealing properties.

God Bless
Bill
https://www.jalopyjournal.com/forum/...closed.614419/

Re: Best Filler to use over Leadwork
 

If you want to see a video on how to do lead watch the Gene Winfield instructions on U tube for Eastwood

Re: Best Filler to use over Leadwork
 

The Lead Master! - Bill Hines - The Leadslinger
https://external-content.duckduckgo....bd98b94a16d044

Re: Best Filler to use over Leadwork
 

I have a '66 GT350 that has factory welded seems where they attached the quarter panels to the roof and trunk area. The factory did a pretty bad job; the leaded seams were really wavy. I filed the high spots and scratch the leaded surface, so the plastic filer had something to adhere to. That was 35-years ago, and it still looks good. I can't remember what filler I used but I cleaned the lead really good before I put the filler over it. At the time I had taken a college autobody class. I had decided that a very thin amount of plastic filler over small dents was better than lead. Lead looks really professional, but I think plastic filler is better in the long run. I try to metal finish dents the best I can but there rarely perfect so I get it the best I can and then put a thin coating of filler over it. I've decided thin coat of filler is better than grinding and pounding on the dent trying to make it perfect but at the same time I'm making the metal thinner. I just don't do metal work enough to be really good at it. I pound out the dent, shrink the high spots, lightly file it to find any more low spots, clean the metal really good and then smear the filler on it. The products they have now are a lot better than what they had 35-years-ago, they are also a lot more expensive.